Apparatus for directional drilling of wells



2 Sheets-Shea?l 1 July 24, 1962 w. G. KLAssEN APPARATUS FOR DIRECTIONAL. DRILLING OF WELLS Filed Nov. 28, 1958 July 24, 1962 w. G. KLASSEN APPARATUS FOR DIRECTIONAL. DRILLING oF WELLS 2 Sheets-Sheet 2 Filed NOV. 28, 1958 VAVQVQAYVAYK vf.

,A m m/A wip wu/5 G. 44451451/ wardly on mandrel 11, against the force of compression spring 41, so that the clutch teeth 42 and 43 formed on the lower cage ring 22 and piston sleeve 36, respectively, will become disengaged, as shown in FIG. 2. Conversely, when the force of spring 41 exceeds the pressure within chamber 37, the piston sleeve will be forced upwardly by spring 41 to engage the clutch teeth 42 and 43, as shown in FIG. 3. Thus, means operated by the fluid pressure, which is applied from the top of the well, is provided for selectively coupling sleeve 20 to said drill pipe.

The piston sleeve 36 and the bottom sub 16 are provided with interengaging longitudinal splines 44 and 45, respectively, which allow the piston sleeve to move longitudinally along mandrel 11 between the positions shown in FIGS. 2 and 3, while preventing rotation of the piston sleeve relative to the bottom sub 16 and the mandrel 11.

Referring now to FIG. 5, wherein the stabilizer 1i) is shown in a well bore 50, it is to be noted that the lateral distance from the center 51 of the stabilizer 10 to the outermost edge 52 of the stabilizer wing 25 is greater than the radius r of the well bore. Thus the stabilizer will be held offset from the well bore axis by the stabilizer wing 25. It has been found that a half inch offset is a practicable amount, but the invention is not restricted to such an amount. The bow spring 39 normally holds the stabilizer wing 25 in engagement with the well bore 50.

The side wings 23 and 24 preferably form an angle of about 80 with the wing 25 so as to enable the stabilizer 10 to move laterally in the bore 50 in a direction away from the engagement of wing 25 therewith, without undue interference of wings 23 and 24 with the well bore during such movement.

As will be seen from the above description, the stabilizer sleeve 20 is free to rotate on mandrel 11 but is prevented from moving longitudinally thereon. Also, the piston sleeve 36 is capable of moving longitudinally on mandrel 11 but is restrained from rotating relative thereto.

Turning now to FIGS. 6, 7 and 8, in the operation of drilling the well bore 50, a drill string is assembled, comprising from the bottom up: `a conventional drill bit 55, a lower rigid stabilizer 56, a non-magnetic drill collar 17, the controllable stabilizer 1), a modified drill collar 14, an upper rigid stabilizer 57 and drill pipe 5S extending to the top of the well.

The lower and upper rigid stabilizers 56 and 57 `act to center the drill string in the `well bore 50 below and above the directional stabilizer 10. These rigid stabilizers are commonly employed in well drilling.

The modified drill collar 14 is made from a conventional I drill collar by reducing its wall thickness to increase lateral flexibility. This provides an increase in the bend thereof when the drill bit 55 is bottomed in the well and sufficient weight is applied thereto. Accordingly, the well string is provided with a flexible portion (drill collar 14) between stabilizers 56 and 57.

The drill string 15 is illustrated in FIG. 6 in normal drilling position in the well bore Sil with enough of the weight of the drill string being supported at the top of the well to prevent lateral deflection of the modified drill collar 14. The bow spring 30 of the directional stabilizer 10 holds the wing 25 thereof against the wall of the well bore so that the axis of the drill string is but very slightly offset at that point from the axis of the well bore. The pressure of the drilling fluid pressing down through the drill string is exerted in the piston chamber 37 to force the piston sleeve 36 downwardly in order to disengage the clutch teeth 42 and 43. Such disengagement permits rotation of the drill string, including mandrel 11, while the stabilizer sleeve remains stationary in the well bore.

After drilling has proceeded for a desired time, a conventional double magnetic survey instrument is run down the drill string so that the upper survey instrument is positioned adjacent the magnets 33 and 34 contained in the upper wing cage 21 and so that the lower survey instrument is positioned in the non-magnetic drill collar 17. The lower survey instrument will record the `amount of well bore deviation from vertical and the direction of such deviation, and the upper survey instrument will record the relationship of the permanent magnets 34 and 35 relative to Magnetic North. This latter recording will thus enable the relationship of the bow spring 30 to Magnetic North to be found.

The above surveying is generally performed with the drill string raised off of the bottom of the well bore, as illustrated in FIG. 7. The circulation of drilling fluid through the drill string is temporarily stopped decreasing the pressure in the piston chamber 37, which enables spring 41 to move the piston sleeve 36 upwardly so that the clutch teeth 42 and 43 will be engaged with one another.

An appraisal of the readings of the double survey will then indicate the necessity for deilecting further drilling. If it is determined that the well bore requires deviating, the drill string is rotated from the top of the well through a proper amount to orient the directional stabilizer sleeve 2t) so that the bow spring 30 thereof engages the well bore on the side thereof opposite to the direction in which the well bore is desired to be drilled. So positioned, the stabilizer wing 25 will force the axis of the stabilizer 10 away from the axis of the well bore in a direction opposite to the direction of desired further drilling. If desired, an additional survey may be made to assure that the stabilizer 1f) is properly oriented.

The drill string is again lowered in the well bore to position the drill bit at the bottom of the well and the circulation of the drilling fluid is recommended, causing the clutch 42, 43 to disengage. Rotation of the drill string is again begun and sufficient weight is placed upon the modified drill collar 14 such as to cause it to laterally bend. Since the directional stabilizer 10 is already offset from the axis of the well, the bending of the drill collar 14 will collapse the bow spring inwardly towards mandrel 11 so that the axis of the directional stabilizer 10 becomes even more odset from the well bore axis, as depicted in FIG. 8.

Further drilling will cause the drill bit to drill in a direction along the arc defined by the centers of the two rigid stabilizers 56 and 57 and the center of the directional stabilizer 10 which latter member will not rotate with the drill string due to the disengagement of the clutch teeth 42 and 43. The drilling will be continued in this direction until a later survey reveals the necessity for changing the further direction of drilling, at which time the direction may be rechanged as above described, so that drilling may be resumed in the newly desired direction.

As may be seen from the foregoing, the present invention greatly reduces the time and expense in directional drilling by eliminating the necessity for pulling the drill string whenever it is desired to deviate the drilling from a former direction of drilling.

It is to be realized that the invention herewith shown and described is a preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the attached claims. As, for example, FIG. 6 shows the modified drill collar 14 as being attached to the upper rigid stabilizer 57. However, one or more steel drill collars could be coupled between the modified drill collar 14 and the stabilizer 57 in order to provide more weight. Other modifications will be apparent to those skilled in the art.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A directional stabilizer for use in directional drilling in a well bore having a given radius comprising a tubular mandrel adapted to be connected in a drill string, a first annular sleeve member mounted on said mandrel for free relative rotation therewith and fixed against longitudinal movement thereon, a second annular sleeve member mounted on said drill member for longitudinal movement thereon and fixed against relative rotation therewith, spring means resiliently biasing said sleeve members into engagement with each other, interengageable clutch means on said sleeve members for preventing relative rotation therebetween when in engagement with each other, said mandrel having a lateral opening therethrough, means forming a variable capacity piston chamber between said second sleeve member and said mandrel and in communication with said mandrel opening so that introduction of fluid pressure from said mandrel into said chamber will move said second sleeve member out of engagement with said first sleeve member, an outwardly extending spacing member rigidly mounted on said first sleeve member, the distance from the axis of said first sleeve member to the outermost part of said spacing member being greater than said well bore radius, and a vertically elongated, outwardly extending and inwardly collapsible bow spring means mounted on said first sleeve on the side thereof opposite to said spacing member.

2. A directional stabilizer for use in directional drilling in a well bore having a given radius comprising a tubular mandrel adapted to be connected in a drill string, a first annular sleeve member mounted on said mandrel for free relative rotation therewith and fixed against longitudinal movement thereon, a second annular sleeve member mounted on said drill member for longitudinal movement thereon and fixed against relative rotation therewith, spring means resiliently biasing said sleeve members into engagement with each other, interengageable clutch means on said sleeve members for preventing relative rotation therebetween when in engagement with each other, said mandrel having a lateral opening therethrough, means forming a variable capacity piston chamber between said second sleeve member and said mandrel and in communication with said mandrel opening so that introduction of fluid pressure from said mandrel into said chamber will move said second sleeve member out of engagement with said first sleeve member, a vertically elongated and outwardly extending spacing member rigidly mounted on said first sleeve member, the distance from the axis of said first sleeve member to the outermost part of said spacing member being greater than said well bore radius, a vertically elongated, outwardly extending and inwardly collapsible spring means mounted on said first sleeve on the side thereof opposite to said spacing member, and vertically elongated and outwardly extending fins mounted on opposite sides of said first sleeve between said spring member and spring means.

3. A directional stabilizer for use in directional drilling in a. well bore having a given radius comprising a tubular mandrel adapted to be connected in a drill string, a first annular -sleeve member mounted on said mandrel for free relative rotation therewith and fixed against longitudinal movement thereon, a second annular sleeve member mounted on said drill member for longitudinal movement thereon and fixed against relative rotation therewith, spring means resiliently biasing said sleeve members into engagement with each other, interengageable clutch means on said sleeve members for preventing relative rotation therebetween when in engagement with each other, said mandrel having a lateral opening therethrough, means forming a variable capacity piston chamber between said second sleeve member and said mandrel and in communication with said mandrel opening so that introduction of fluid pressure from said mandrel into said chamber will move said second sleeve member out of engagement with said first sleeve member, a vertically elongated and outwardly extending spacing member rigidly mounted on said first sleeve member, the distance from the axis of said first sleeve member to the outermost part of said spacing member being greater than said well bore radius, said first sleeve having a portion thereof made of non-magnetic material, and magnet means mounted in said non-magnetic sleeve portion, said mandrel having the portion thereof adjacent said magnet means made of non-magnetic material.

4. -A directional stabilizer for use in directional drilling in a well bore having a given radius comprising a tubular mandrel adapted to be connected in a drill string, a first annular sleeve member mounted on said mandrel ffor free relative rotation therewith, 4a second annular sleeve member mounted on said drill member and fixed against relative rotation therewith, means to allow longitudinal movement of at least one of said sleeve members along said mandrel so that said sleeve `members may be engaged with one another, spring means resiliently biasing said sleeve members into engagement with each other, interengageable clutch means on said sleeve members for preventing relative rotation therebetween when in engagement with each other, said mandrel having a lateral opening therethrough, means forming a variable capacity piston chamber 'between the longitudinally movable sleeve member and said mandrel and in communication with said mandrel opening so that introduction of sufiicient fluid pressure from said mandrel through said opening and into said chamber will move said longitudinally movable sleeve member out of engagement with the other sleeve member, a vertically elongated and outwardly extending spacing member rigidly mounted on said first sleeve member, the distance `from the axis of said irst sleeve member to the outermost part of said spacing member being greater than said `well bore radius, a vertically elongated, outwardly extending and inwardly collapsible bow spring means mounted on said first sleeve on the side thereof opposite to said spacing member, vertically elongated and outwardly extending ns mounted on opposite sides of said first sleeve between said spring member and spring means, said first sleeve having a portion thereof made of non-magnetic material, and magnet means mounted in said non-magnetic sleeve portion, said mandrel having the portion thereof adjacent said magnet means made of nonmagnetic material.

5. Apparatus for directional drilling in a well bore comprising: a drill string adapted to be lowered into said well bore; stabilizing means mounted upon said string at vertically spaced points for centering the drill string in the well bore, said means providing well bore engaging surfaces, Iand a directional stabilizer rotatably mounted upon said string at a point intermediate said vertically spaced points for displacing a portion of said string away from the central axis of said well bore, said stabilizer comprising a tubular mandrel connected in said drill string, a first annular sleeve member mounted on said mandrel for free relative rotation therewith, a second annular sleeve member mounted on said mandrel and fixed against relative rotation therewith, means to allow longitudinal movement of at least one of said sleeve members along said mandrel so that said sleeve members may be engaged with each other, means resiliently biasing said sleeve members into engagement with each other, interengageable clutch means on said sleeve members for preventing relative rotation therebetween when in engagement with each other, means responsive to a predetermined liuid pressure within said mandrel for moving said sleeve members against the bias of said biasing means and out of engagement with each other, and an outwardly extending spacing member mounted on said first sleeve member, the distance from the axis of said first sleeve member to the outermost part of said spacing member being greater than said well bore radius.

6. Apparatus for directional drilling in a well bore comprising: a drill string adapted to be lowered into said well bore; stabilizing means mounted upon said string at vertically spaced points for centering the drill string in the well bore, said means providing well bore engaging surfaces, and a directional stabilizer rotatably mounted upon said string at a point intermediate said vertically spaced points for displacing a portion of said string away from the central axis of said well bore, said stabilizer comprising a tubular mandrel connected in said drill string, a first annular sleeve member mounted on said mandrel for free relative rotation therewith, means preventing relative longitudinal movement between said first sleeve and said mandrel, a second annular sleeve member mounted on said mandrel and fixed against relative rotation therewith, means to allow longitudinal movement of said second sleeve member along said mandrel into and out of engagement with said first sleeve member, spring means resiliently biasing said second sleeve member into engagement with said rst sleeve member, interengageable clutch means on said sleeve members for preventing relative rotation therebetween when in engagement with each other, means responsive to a predetermined fluid pressure within said mandrel for moving said sleeve members against the bias of said Ispring means and out of engagement with each other, and a vertically elongated and outwardly extending spacing member rigidly mounted on said first sleeve member, the distance from the axis of said `first sleeve member to the outermost part of said spacing member being greater than said well bore radius.

7. Apparatus for directional drilling in a well bore comprising a drill string adapted to be lowered to the bottom of said well bore, a pair of vertically spaced-apart stabilizers connected in said drill string for centering said drill string in said well bore, said drill string having a laterally llexible portion provided between said stabilizers,

a stabilizer sleeve rotatably mounted on said drill string between said stabilizers, outwardly extending spacing means on said sleeve engagea-ble with said well bore for normally holding said sleeve and the drill pipe therewithin at least slightly displaced from the center of the well bore, `clutch means for releasably engaging said drill string and stabilizer sleeve together to prevent relative rotation therebetween in either direction, spring means for normally engaging said clutch means, and means operable by a predetermined magnitude of uid pressure within said drill string for releasing said clutch means to disengage said drill string and stabilizer sleeve for relative rotation therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 2,061,316 Brack et a1 Nov. 17, 1936 2,120,670 Hyer June 14, 1938 2,316,409 Downing Apr. 13, 1943 2,327,658 Miller Aug. 24, 1943 2,711,879 Ring June 28, 1955 2,712,434 Giles et al July 5, 1955 2,745,635 zub1in M'ay 15, 1956 2,805,840 Thompson Sept. l0, 1957 2,819,040 James et al Jan. 7, 1958 2,829,864 Knapp Apr. 8, 1958 2,915,286 Wright Dec. 1, 1959 

